Watermelon variety NUN 31208 WMW

ABSTRACT

The invention relates to the field of  Citrullus lanatus , in particular to a new variety of watermelon designated NUN 31208 WMW as well as plants, seeds and watermelon fruits thereof.

FIELD OF THE INVENTION

The present invention relates to the field of plant breeding and, morespecifically, to the development of watermelon variety NUN 31208 WMW,also referred to as “NUN 31208”, “NUN 31208 F1”, “NUN 31208 hybrid” andparts thereof and seeds from which the variety can be grown. Theinvention further relates to vegetative reproductions of NUN 31208,methods for in vitro tissue culture of NUN 31208 explants and also tophenotypic variants of NUN 31208WMW. The invention further relates tomethods of producing triploid, seedless watermelon fruits of NUN 31208or of phenotypic variants of NUN 31208 WMW.

The goal of vegetable breeding is to combine various desirable traits ina single variety/hybrid. Such desirable traits may include greateryield, resistance to insects or pests, tolerance to heat and drought,desired earliness, seedless fruits, better agronomic quality, highernutritional value, growth rate and fruit properties.

Breeding techniques take advantage of a plant's method of pollination.There are two general methods of pollination: a plant self-pollinates ifpollen from one flower is transferred to the same or another flower ofthe same plant or plant variety. A plant cross-pollinates if pollencomes to it from a flower of a different plant variety.

Plants that have been self-pollinated and selected for type over manygenerations become homozygous at almost all gene loci and produce auniform population of true breeding progeny, a homozygous plant. A crossbetween two such homozygous plants of different varieties produces auniform population of hybrid plants that are heterozygous for many geneloci. Conversely, a cross of two plants each heterozygous at a number ofloci produces a population of hybrid plants that differ genetically andare not uniform. The resulting non-uniformity makes performanceunpredictable.

The development of uniform varieties requires the development ofhomozygous inbred plants, the crossing of these inbred plants, and theevaluation of the crosses. Pedigree breeding and recurrent selection areexamples of breeding methods that have been used to develop inbredplants from breeding populations. Those breeding methods combine thegenetic backgrounds from two or more plants or various other broad-basedsources into breeding pools from which new lines are developed byselfing and selection of desired phenotypes. The new lines are evaluatedto determine which of those have commercial potential.

One crop species which has been subject to such breeding programs and isof particular value is the watermelon. It is a member of theCucurbitacea family. The genus Citrullus originated in Africa. The plantis a large and sprawling annual, grown for its fruit. The fruit of mostspecies of Citrullus is often coloured attractively, commonly red.Watermelon can contain black seeds, which are considered undesirable forcertain uses.

Many different watermelon cultivars have been produced, and watermelonbreeding efforts have been underway in many parts of the world. Somebreeding objectives include varying the color, texture and flavor of thefruit, and absence of seeds. Other objectives include disease or pestresistance, optimizing flesh thickness, yield, suitability to variousclimatic circumstances, solid content (% dry matter), and sugar content.

Watermelon (Citrullus lanatus) can occur as a dipoloid, tripoid ortetraploid. Seedless watermelon (Citrullus lanatus (Thunb.) Matsum. AndNak.) are produced by using pollen from diploid male parent plants tofertilize flowers of tetraploid maternal parent plants. Pollination ofthe tetraploid flowers with diploid pollen leads to hybrid F1 seedswhich are triploid (Kihara, 1951, Proceedings of American Society forHorticultural Science 58: 217-230; Eigsti 1971, Hort Science 6: 1-2).The triploid hybrid plants grown from these F1 seeds are self-infertileas they produce sterile pollen due to chromosome imbalance. The triploidhybrids, therefore, need to be pollinated by a diploid pollenizer toproduce watermelon fruit. Triploid plants are, therefore, interplantedwith pollenizer plants for fruit production. The “seedless” fruitproduced after pollination on the triploid hybrid plant are not trulyseedless, but often contain some undeveloped, small, pale seeds, whichare edible.

For optimal fruit set, sufficient viable pollen is required. Plants aregenerally planted at a ratio of 1 pollenizer per every 2-4 triploidplants. Triploid plants and pollenizers are either planted in separaterows (e.g. 1 row of pollenizer and 2-4 rows of triploids), orinterplanted within rows (e.g. planting 1 pollenizer plant in between 2to 3 triploid plants in the same row), or interplanted in narrow rowsbetween rows of triploids (see US 2006/0168701 Table 2). The fruitproduced on the pollenizer plants preferably has a different rindpattern from the fruit on the triploid hybrids, so that these can beeasily distinguished.

Although hybrid triploid (seedless) watermelons have been grown in theUnited States for over 40 years, there is still a need for improvedvarieties. Consumer demand is high, and the seedless fruit of triploidwatermelons are very desired, both for the fresh and the processedmarket. Many different triploid watermelon varieties exist (see e.g.world wide web at cuke.hort.ncsu.edu/cucurbit/wmelon/wmcultab.html),producing fruits of different sizes and shapes, as well as differentfruit quality. Grading of fruits is usually done by fruit weight, todistinguish “mini” watermelons, with weights of less than 6 pounds (2.72kg), “icebox” watermelons with weights of 8-12 pounds (3.62 kg-5.44 kg)or, according to others, of 6 to 15 pounds (2.72 kg to 6.8 kg) and“picnic” watermelons of above the icebox size, so either above 12 lb(above 5.44 kg) or above 15 pounds (above 6.8 kg).

SUMMARY OF THE INVENTION

In one aspect of the invention, a seed of watermelon variety NUN 31208WMW is provided, wherein a representative sample of said seed has beendeposited under Accession Number NCIMB 42970.

In another aspect the invention provides for a hybrid variety ofCitrullus lanatus called NUN 31208 WMW. The invention also provides fora plurality of seeds of the new variety, plants produced from growingthe seeds of the new variety NUN 31208 WMW, and progeny of any of these.Especially, progeny retaining one or more (or all) of the“distinguishing characteristics” or one or more (or all) of the“essential morphological and physiological characteristics” oressentially all physiological and morphological characteristics of NUN31208 WMW referred to herein, are encompassed herein as well as methodsfor producing these.

In one aspect, such progeny have all the physiological and morphologicalcharacteristics of watermelon variety NUN 31208 WMW when grown under thesame environmental conditions. In another aspect such progeny have allthe physiological and morphological characteristics as listed in Table 1as watermelon variety NUN 31208 WMW when measured under the sameenvironmental conditions (i.e. evaluated at significance levels of 1%,5% or 10% significance, which can also be expressed as a p value).

In another aspect a plant of the invention or said progeny plantshas/have 1, 2, 3, 4 or more or all of the distinguishing characteristicsselected from the group consisting of: 1) a mature fruit length of about24.3 cm (e.g., between 23.1 cm and 25.5 cm); 2) a mature fruit averageweight of about 6.4 kg (e.g., between 6.1 kg and 6.7 kg); 3) a maturefruit rind thickness at blossom end of about 5.9 mm (e.g., between 5.6mm and 6.2 mm); 4) a mature fruit rind side thickness of about 9.6 mm(e.g., between 9.1 mm and 10.1 mm); 5) maturity category 2—medium (e.g.,80-90 days); 6) a number of main stems at crown of about 3.1 (e.g.,between 2.9 and 3.3); 7) a mature fruit flesh color that is type 6—DarkRed; and, 8) a mature fruit primary skin color that is type 1—YellowGreen (Desert King). In another aspect a plant of the invention has, inaddition to the 1, 2, 3, 4 or more or all of the above-citeddistinguishing characteristics, 3, 4, 5, 6, 7, 8, or more, or all of theother (average) characteristics as listed in Table 1.

Further, a watermelon fruit produced on a plant grown from these seedsis provided.

In yet another embodiment of the invention, a plant having one, two orthree physiological and/or morphological characteristics which aredifferent from those of NUN 31208 WMW and which otherwise has all thephysiological and morphological characteristics of NUN 31208 WMW aslisted in Table 1, wherein a representative sample of seed of varietyNUN 31208 WMW has been deposited under Accession Number NCIMB 42970, isprovided.

Further, a vegetatively propagated plant of variety NUN 31208 WMW, or apart thereof, is provided having all the morphological and physiologicalcharacteristics of NUN 31208 WMW when grown under the same environmentalconditions.

Also a plant part derived from variety NUN 31208 is provided, whereinsaid plant part is selected from the group consisting of: fruit,harvested fruit, parts of fruits, leaf, pollen, ovule, cell, part of aleaf, petioles, shoots or parts thereof, stems or parts thereof, vinesor parts thereof, roots or parts thereof, cuttings, seeds, hypocotyl,cotyledon, flowers or parts thereof, scion, cion, stock, rootstock andflower. Fruits are particularly important plant parts.

DEFINITIONS

“Watermelon” refers herein to plants of the species Citrullus lanatus,and fruits thereof.

“Cultivated watermelon” refers to plants of Citrullus lanatus i.e.varieties, breeding lines or cultivars of the species C. lanatus as wellas crossbreds thereof, or crossbreds with other Citrullus species, oreven with other Cucurbitacea species, cultivated by humans and havinggood agronomic characteristics; preferably such plants are not “wildplants”, i.e. plants which generally have much poorer yields and pooreragronomic characteristics than cultivated plants and e.g. grow naturallyin wild populations. “Wild plants” include for example ecotypes, PI(Plant Introduction) lines, landraces or wild accessions or wildrelatives of Citrullus and related species.

The terms “watermelon plant designated NUN 31208”, “NUN 31208” “31208WMW” or “variety designated NUN 31208” are used interchangeably hereinand refer to a watermelon plant of variety NUN 31208 WMW, representativeseed of which having been deposited under Accession Number NCIMB 42970.

“Tissue culture” refers to a composition comprising isolated cells ofthe same or a different type or a collection of such cells organizedinto parts of a plant. Tissue culture of various tissues of watermelonand regeneration of plants therefrom is well known and widely published(see, e.g., Compton et al., Plant Cell, Tissue and Organ Culture 77:231-243, 2004. Similarly, the skilled person is well-aware how toprepare a “cell culture”.

“UPOV descriptors” are the plant variety descriptors described forwatermelon in the “Guidelines for the Conduct of Tests for Distinctness,Uniformity and Stability, TG/142/5 (Geneva, 2013), as published by UPOV(International Union for the Protection of New Varieties and Plants,available on the world wide web at upov.int) and which can be downloadedfrom the world wide web at upov.int/ under edocs/tgdocs/en/tg142.pdf andis herein incorporated by reference in its entirety.

“USDA descriptors” are the plant variety descriptors for watermelon(Citrullus lanatus) as published by the US Department of Agriculture,Agricultural Marketing Service, Plant Variety Protection Office,Beltsville, Md. 20705 (available on the world wide web at ams.usda.gov)and which can be downloaded from the world wide web atams.usda.gov/AMSv1.0/getfile?dDocName=STELDEV3003729.

“RHS” refers to the Royal Horticultural Society of England whichpublishes an official botanical color chart quantitatively identifyingcolors according to a defined numbering system. The chart may bepurchased from Royal Horticulture Society Enterprise Ltd RHS Garden;Wisley, Woking; Surrey GU236QB, UK, e.g., the RHS colour chart: 2007(The Royal Horticultural Society, charity No: 222879, PO Box 313 LondonSW1P2PE; sold by, e.g., TORSO-VERLAG, Obere Grüben 8⋅D-97877 Wertheim,Article-No.: Art62-00008 EAN-Nr.: 4250193402112).

As used herein, the term “plant” includes the whole plant or any partsor derivatives thereof, preferably having the same genetic makeup as theplant from which it is obtained, such as plant organs (e.g. harvested ornon-harvested fruits), plant cells, plant protoplasts, plant cell tissuecultures or tissue cultures from which whole plants can be regenerated,plant calli, plant cell clumps, plant transplants, seedlings, hypocotyl,cotyledon, plant cells that are intact in plants, plant clones ormicropropagations, or parts of plants (e.g. harvested tissues ororgans), such as plant cuttings, vegetative propagations, embryos,pollen, ovules, fruits, flowers, leaves, seeds, clonally propagatedplants, roots, stems, vines, root tips, grafts, scions, rootstocks,parts of any of these and the like. Also any developmental stage isincluded, such as seedlings, cuttings prior or after rooting, matureplants or leaves.

“Harvested plant material” refers herein to plant parts (e.g. fruitsdetached from the whole plant) which have been collected for furtherstorage and/or further use.

“Harvested seeds” refers to seeds harvested from a line or variety, e.g.produced after self-fertilization or cross-fertilization and collected.

“Internode” refers to a portion of a plant stem or vine between nodes.

“Node” refers to the place on a plant stem or vine where a leaf isattached.

A plant having “all the physiological and morphological characteristics”of a referred-to-plant means a plant having the physiological andmorphological characteristics of the referred-to-plant when grown underthe same environmental conditions; the referred-to-plant can be a plantfrom which it was derived, e.g. the progenitor plant, the parent, therecurrent parent, the plant used for tissue- or cell culture, etc.

A plant having “essentially all the physiological and morphologicalcharacteristics” of a referred-to-plant means a plant having at least 5(e.g. 6, 7, 8, 9 or all) of the distinguishing physiological andmorphological characteristics (distinguishing characteristics as hereindefined) when grown under the same environmental conditions of thereferred-to-plant (e.g. a plant from which it was derived such as theprogenitor plant, the parent, the recurrent parent, the plant used fortissue- or cell culture, etc.). Alternatively, a plant having“essentially all the physiological and morphological characteristics” ofa referred-to-plant means a plant having all the characteristics aslisted in Table 1 when grown under the same environmental conditions asa referred-to-plant (e.g. a plant from which it was derived such as theprogenitor plant, the parent, the recurrent parent, the plant used fortissue- or cell culture, etc.). In another embodiment, a plant having“essentially all the physiological and morphological characteristics” ofa referred-to-plant means a plant having all but 1, 2, 3, 4 or 5 of thecharacteristics as listed in Table 1 when grown under the sameenvironmental conditions as a referred-to-plant (e.g. a plant from whichit was derived such as the progenitor plant, the parent, the recurrentparent, the plant used for tissue- or cell culture, etc.).

For NUN 31208 WMW the distinguishing characteristics are: 1) maturefruit length; 2) mature fruit average weight; 3) mature fruit rindthickness at blossom end; 4) mature fruit rind side thickness; 5)maturity category; 6) number of main stems at crown; 7) mature fruitflesh color and 8) mature fruit primary skin color.

In certain embodiments the plant of the invention has all thephysiological and morphological characteristics, except for certaincharacteristics mentioned, e.g. the characteristic(s) derived from aconverted or introduced gene or trait and/or except for thecharacteristics which differ.

Similarity between different plants is defined as the number ofdistinguishing characteristics (or the characteristics as listed inTable 1) that are the same between the two plants that are compared whengrown under the same environmental conditions. Characteristics areconsidered “the same” when the value for a numeric characteristic isevaluated at significance levels of 1%, 5% or 10% significance level, orwhen a non-numeric characteristic is identical, if the plants are grownunder the same conditions.

A plant having one or more “essential physiological and/or morphologicalcharacteristics” or one or more “distinguishing characteristics” refersto a plant having (or retaining) one or more of the characteristicsmentioned in Table 1 when grown under the same environmental conditionsthat distinguish NUN 31208 WMW from the most similar varieties (such asvariety Liberty), such as but not limited to average number of fruitsper plant, fruit flavor and texture, maturity, average flower diameteror average vine length.

“Distinguishing characteristics” or “distinguishing morphological and/orphysiological characteristics” refers herein the characteristics whichare distinguishing between NUN 31208 WMW and other watermelon varieties,such as Liberty, when grown under the same environmental conditions,especially the following characteristics: 1) a mature fruit length ofabout 24.3 cm (e.g., between 23.1 cm and 25.5 cm); 2) a mature fruitaverage weight of 6.4 kg (e.g., between 6.1 kg and 6.7 kg); 3 a maturefruit rind thickness at blossom end of about 5.9 mm (e.g., between 5.6mm and 6.2 mm); 4) a mature fruit rind side thickness about 9.6 mm (e.g.between 9.1 mm and 10.1 mm); 5) a maturity category 2—medium (e.g.,80-90 days); 6) a number of main stems at crown of about 3.1 (e.g.,between 2.9 and 3.3); 7) a mature fruit flesh color that is type 6—DarkRed; and, 8) a mature fruit primary skin color that is type 1—YellowGreen (Desert King). In one aspect, the distinguishing characteristicsfurther include at least one, two, three or more (or all) of thecharacteristics listed in Table 1. All numerical distinguishingcharacteristics are statistically significantly different at p≤0.05.

Thus, a watermelon plant “comprising the distinguishing characteristicsof NUN 31208 WMW” refers herein to a watermelon plant which does notdiffer significantly from NUN 31208 WMW in characteristics 1) to 4)above. In a further aspect the watermelon plant further does not differsignificantly from NUN 31208 WMW in one or more, or all characteristics5) to 8) as mentioned above. In yet a further aspect the watermelonplant further does not differ in at least one, two, three, four, five orsix (or all) characteristics selected from the characteristics listed inTable 1. In still another aspect the watermelon plant does not differ inany of the distinguishing characteristics 1) to 8) listed above.

The physiological and/or morphological characteristics mentioned aboveare commonly evaluated at significance levels of 1%, 5% or 10%, whenmeasured under the same environmental conditions. For example, a progenyplant of NUN 31208 WMW may have one or more (or all) of the essentialphysiological and/or morphological characteristics of NUN 31208 WMWlisted in Table 1, as determined at the 5% significance level (i.e.p≤0.05) when grown under the same environmental conditions.

As used herein, the term “variety” or “cultivar” means a plant groupingwithin a single botanical taxon of the lowest known rank, whichgrouping, irrespective of whether the conditions for the grant of abreeder's right are fully met, can be defined by the expression of thecharacteristics resulting from a given genotype or combination ofgenotypes, distinguished from any other plant grouping by the expressionof at least one of the said characteristics and considered as a unitwith regard to its suitability for being propagated unchanged.

“Plant line” is for example a breeding line which can be used to developone or more varieties. Progeny obtained by selfing a plant line has thesame phenotype as its parents.

“Hybrid variety” or “F1 hybrid” refers to the seeds harvested fromcrossing two inbred (nearly homozygous) parental lines. For example, thefemale parent is pollinated with pollen of the male parent to producehybrid (F1) seeds on the female parent.

“Regeneration” refers to the development of a plant from cell culture ortissue culture or vegetative propagation.

“Vegetative propagation”, “vegetative reproduction” or “clonalpropagation” are used interchangeably herein and mean the method oftaking part of a plant and allowing that plant part to form at leastroots where plant part is, e.g., defined as or derived from (e.g. bycutting of) leaf, pollen, embryo, cotyledon, hypocotyl, cells,protoplasts, meristematic cell, root, root tip, pistil, anther, flower,shoot tip, shoot, stem, vines, fruit, petiole, etc. When a whole plantis regenerated by vegetative propagation, it is also referred to as avegetative propagation.

“Planting” or “planted” refers to seeding (direct sowing) ortransplanting seedlings (plantlets) into a field by machine or hand.

“Interplanting” refers to the combination of two or more types of seedsand/or transplants sown or transplanted (or planted) on the same field,especially the sowing and/or transplanting (or planting) of pollenizersin the same field as triploid hybrid plants (for seedless fruitproduction on the triploid plants and diploid fruit production on thepollenizer plants). For example, the pollenizer may either be planted inseparate rows or interplanted with the triploid plants in the same row(e.g. in hills within each row). Pollenizers may also be planted inbetween rows of triploids. Also seeds of pollenizers and triploidhybrids may be mixed prior to seeding, resulting in random seeding. Thetransplants of the triploid hybrid plants and/or pollenizer plants mayalso comprise a rootstock of a different plant. Suitable rootstocks areknown in the art. Watermelon plants with a different rootstock arereferred to as “grafted”.

“Yield” means the total weight of all watermelon fruits harvested perhectare of a particular line or variety. It is understood that “yield”expressed as weight of all watermelon fruits harvested per hectare canbe obtained by multiplying the number of plants per hectare times the“yield per plant”.

“Marketable yield” means the total weight of all marketable watermelonfruits, especially seedless triploid fruit of at least 2.5 kg, harvestedper hectare of a particular line or variety, i.e. fruits suitable forbeing sold for fresh consumption, having good flavor (no off-flavors),at least 10% brix (or Total Soluble Solids, TSS, as determined using arefractometer) and flesh color properties and no or very low levels ofdeficiencies such as hollow heart.

“Selfing” refers to self-pollination of a plant, i.e., the transfer ofpollen from the anther to the stigma of the same plant. “Crossing”refers to the mating of two parent plants.

“Average” refers herein to the arithmetic mean.

The term “about” in relation to a particular value refers to said value+/−5%, i.e. to a range between said value minus 5% of said value andsaid value plus 5% of said value.

“Substantially equivalent” refers to a characteristic that, whencompared, does not show a statistically significant difference (e.g.,p=0.05) from the mean. ANOVA is a suitable method for determining thevalue of p.

“Locus” (plural loci) refers to the specific location of a gene or DNAsequence on a chromosome. A locus may confer a specific trait.

“Allele” refers to one or more alternative forms of a gene locus. All ofthese loci relate to one trait. Sometimes, different alleles can resultin different observable phenotypic traits, such as differentpigmentation. However, many variations at the genetic level result inlittle or no observable variation. If a multicellular organism has twosets of chromosomes, i.e. diploid, these chromosomes are referred to ashomologous chromosomes. Diploid organisms have one copy of each gene(and therefore one allele) on each chromosome. If both alleles are thesame, they are homozygotes. If the alleles are different, they areheterozygotes.

“Genotype” refers to the genetic composition of a cell or organism.

“Maturity” refers to the fruit developmental stage when the fruit hasfully developed (reached its final size), begins to ripen and undergoesripening, during which fruits can be divided into 1, 2, 3 or morematurity stages. Thereafter, fruits become overripe. In particularembodiments “maturity” is defined as the mature stage of fruitdevelopment and optimal time for harvest. In one embodiment a “mature”watermelon is defined as having reached the stage of maturity which willinsure the proper completion of the normal ripening process. Inparticular embodiments, fruit should be harvested at a maturity stagei.e. substantially near maximum sweetness and flavor intensity.

“Harvest maturity” is referred to as the stage at which a watermelonfruit is ripe or ready for harvest or the optimal time to harvest thefruit. In one embodiment, harvest maturity is the stage which allowsproper completion of the normal ripening.

“Flavor” refers to the sensory impression of a food or other substance,especially a watermelon fruit or fruit part (fruit flesh) and isdetermined mainly by the chemical senses of taste and smell. Flavor isinfluenced by texture properties and by volatile and/or non-volatilechemical components (organic acids, lipids, carbohydrates, etc.).

The term “traditional breeding techniques” encompasses herein crossing,selfing, selection, double haploid production, embryo rescue, protoplastfusion, marker assisted selection, mutation breeding etc. as known tothe breeder (i.e. methods other than geneticmodification/transformation/transgenic methods), by which, for example,a genetically heritable trait can be transferred from one watermelonline or variety to another.

“Backcrossing” is a traditional breeding technique used to introduce atrait into a plant line or variety. The plant containing the trait iscalled the donor plant and the plant into which the trait is transferredis called the recurrent parent. An initial cross is made between thedonor parent and the recurrent parent to produce progeny plants. Progenyplants which have the trait are then crossed to the recurrent parent.After several generations of backcrossing and/or selfing the recurrentparent comprises the trait of the donor. The plant generated in this waymay be referred to as a “single trait converted plant”.

“Progeny” as used herein refers to plants derived from a plantdesignated NUN 31208 WMW. Progeny may be derived by regeneration of cellculture or tissue culture or parts of a plant designated NUN 31208 WMWor selfing of a plant designated NUN 31208 WMW or by producing seeds ofa plant designated NUN 31208 WMW. In further embodiments, progeny mayalso encompass plants derived from crossing of at least one plantdesignated NUN 31208 WMW with another watermelon plant of the same oranother variety or (breeding) line, or wild watermelon plants,backcrossing, inserting of a locus into a plant or mutation. A progenyis, e.g., a first generation progeny, i.e. the progeny is directlyderived from, obtained from, obtainable from or derivable from theparent plant by, e.g., traditional breeding methods (selfing and/orcrossing) or regeneration. However, the term “progeny” generallyencompasses further generations such as second, third, fourth, fifth,sixth, seventh or more generations, i.e., generations of plants whichare derived from, obtained from, obtainable from or derivable from theformer generation by, e.g., traditional breeding methods, regenerationor genetic transformation techniques. For example, a second generationprogeny can be produced from a first generation progeny by any of themethods mentioned above.

The terms “gene converted” or “conversion plant” in this context referto watermelon plants which are developed by backcrossing whereinessentially all of the desired morphological and physiologicalcharacteristics of parent are recovered in addition to the one or moregenes transferred into the parent via the backcrossing technique or viagenetic engineering. Likewise a “Single Locus Converted (Conversion)Plant” refers to plants which are developed by plant breeding techniquescomprising or consisting of backcrossing, wherein essentially all of thedesired morphological and physiological characteristics of a watermelonvariety are recovered in addition to the characteristics of the singlelocus having been transferred into the variety via the backcrossingtechnique and/or by genetic transformation.

“Transgene” or “chimeric gene” refers to a genetic locus comprising aDNA sequence which has been introduced into the genome of a watermelonplant by transformation. A plant comprising a transgene stablyintegrated into its genome is referred to as “transgenic plant”.

The term “mean” refers to the arithmetic mean of several measurements.The skilled person understands that the appearance of a plant depends tosome extent on the growing conditions of said plant. Thus, the skilledperson will know typical growing conditions for watermelons describedherein. The mean, if not indicated otherwise within this application,refers to the arithmetic mean of measurements on at least 10 different,randomly selected plants of a variety or line.

“Substantially equivalent” refers to a characteristic that, whencompared, does not show a statistically significant difference (e.g.,p>0.05) from the mean.

DETAILED DESCRIPTION

The present invention relates to a Citrullus lanatus variety, referredto as NUN 31208 WMW, which—when compared to check variety Liberty—hasshorter mature fruit, lighter average mature fruit, fruit that has athinner rind at blossom end, mature fruit that has thinner rind sides,maturity category 2—medium (as compared to maturity category 1—early ofcheck variety Liberty), lower number of main stems at crow, a maturefruit flesh color that is type 6—Dark (as compared to the color type4—Pink of check variety Liberty), a mature fruit primary skin color thatis type 1—Yellow Green (Desert King) (as compared to the type 2—LightGreen (Charleston Grey) of check variety Liberty). Also encompassed bythe present invention are progeny plants having all but 1, 2, or 3 ofthe morphological and/physiological characteristics of NUN 31208 WMW andmethods of producing plants in accordance with the present invention.

A watermelon plant of NUN 31208 WMW differs from the most similarcomparison variety Liberty in one or more characteristics (referredherein to as “distinguishing characteristics” or “distinguishingmorphological and/or physiological characteristics” (or essentialphysiological and/or morphological characteristics) selected from:

1) The mature fruit of NUN 31208 WMW is at least 3%, e.g. at least 4, 5,6% or even 6.9% shorter than the mature fruit of check variety Liberty;

2) The mature fruit of NUN 31208 WMW is at least 10%, e.g. at least 12,13, 14, 15, 16% or even 16.9% lighter than the average mature fruit ofcheck variety Liberty;

3) The mature fruit rind at blossom end of NUN 31208 WMW is at least10%, e.g. at least 10, 15, 20, 22, 23, 24, 25% or even 25.3% thinnerthan the mature fruit rind at blossom end of check variety Liberty;

4) The mature fruit rind of NUN 31208 WMW is at least 5%, e.g. at least7, 15, 15, 17, 18, 19% or even 20% thinner at sides than the maturefruit rind at sides of check variety Liberty;

5) NUN 31208 WMW is in maturity category 2—medium (e.g., 80-90 days) ascompared to maturity category 1—early (e.g., 78-80 days) of checkvariety Liberty;

6) NUN 31208 WMW has a number of main stems at crown that is at least5%, e.g. at least 6, 7, 8, 9, 10, 11% or even 11.4% lower than thenumber of main stems at crown of check variety Liberty;

7) NUN 31208 WMW a mature fruit flesh color that is type 6—Dark Red(e.g., RHS code Red 39A) while check variety Liberty has a mature fruitflesh color type 4—Pink (e.g., RHS code Red 37A); and

8) NUN 31208 WMW has a mature fruit primary skin color that is type1—Yellow Green (Desert King) (e.g., RHS code Yellow Green 150D), ascompared to a mature fruit primary skin color that is type 2—Light Green(Charleston Grey) (e.g., RHS code Yellow Green N144D) of check varietyLiberty.

It is understood that “significant” differences refer to statisticallysignificant differences, when comparing the characteristic between twoplant lines or varieties when grown under the same conditions.Preferably at least about 10, 15, 20 or more plants per line or varietyare grown under the same conditions (i.e. side by side) andcharacteristics are measured on at least about 10, 15, 20 or morerandomly selected plant or plant parts to obtain averages. Thus,physiological and morphological characteristics or traits are commonlyevaluated at a significance level of 1%, 5% or 10%, when measured inplants grown under the same environmental conditions.

Thus, in one aspect, the invention provides seeds of the watermelonvariety designated NUN 31208 WMW wherein a representative sample ofseeds of said variety was deposited under the Budapest Treaty, withAccession number NCIMB 42970.

Seeds of NUN 31208 WMW are obtainable by crossing the male parent withthe female parent and harvesting the seeds produced on the femaleparent. The resultant NUN 31208 WMW seeds can be grown to produce NUN31208 WMW plants. In one embodiment a plurality of NUN 31208 WMW seedsare packaged into small and/or large containers (e.g., bags, cartons,cans, etc.). The seeds may be disinfected, primed and/or treated withvarious compounds, such as seed coatings or crop protection compounds.

Also provided are plants of watermelon variety NUN 31208 WMW, or a fruitor other plant part thereof, produced from seeds, wherein arepresentative sample of said seeds has been deposited under theBudapest Treaty, with Accession Number NCIMB 42970. Also included is acell culture or tissue culture produced from such a plant It isunderstood that such tissue or cell culture comprising cells orprotoplasts from the plant of the invention can be obtained from a plantpart selected from the group consisting of embryos, meristems,cotyledons, hypocotyl, pollen, leaves, anthers, roots, root tips,pistil, petiole, flower, fruit, seed, stem and stalks. In one embodimenta plant regenerated from such a cell or tissue culture said plantexpressing all the morphological and physiological characteristics ofNUN 31208 WMW.

In one embodiment the invention provides a watermelon plant regeneratedfrom the tissue or cell culture of NUN 31208 WMW, wherein the plant hasall of the physiological and morphological characteristics of NUN 31208WMW as listed in Table 1 when determined at the 5% significance level.In another embodiment, the invention provides a watermelon plantregenerated from the tissue or cell culture of NUN 31208 WMW, whereinthe plant has all of the physiological and morphological characteristicsof NUN 31208 WMW when determined at the 5% significance level.

Plants of NUN 31208 WMW can be produced by seeding directly in theground (e.g., field) or by germinating the seeds in controlledenvironment conditions (e.g., greenhouses) and then transplanting theseedlings into the field. For example, the seed can be sown intoprepared seed beds where they will remain for the entire production ofthe crop. Alternatively, the watermelon seed may be planted ortransplanted in prepared mounds.

In another aspect, the invention provides for a watermelon plant ofvariety NUN 31208 WMW, a representative sample of seed from said varietyhas been deposited under the Budapest Treaty, with Accession numberNCIMB 42970.

In other aspects, the invention provides for a fruit or parts thereof ofwatermelon variety NUN 31208 WMW, or a plant part, such as pollen,flowers, shoots or cuttings of variety NUN 31208 WMW or parts thereof.

In one embodiment any plant of the invention comprises at least 3, 4, 5or more, e.g. 6, 7, or all of the following morphological and/orphysiological characteristics (i.e. distinguishing characteristics(average values; measured at harvest or market maturity, as indicated onthe USDA Objective description of variety—Watermelon (unless indicatedotherwise), when grown under the same environmental conditions):

1) NUN 31208 WMW has an average mature fruit length of about 24.3 cm,e.g. between 23 and 26 cm, or between about 23.5 and 25.5 cm, or between24 and 25 cm, or even between 24.2 and 24.4 cm;

2) NUN 31208 WMW has an average mature fruit average weight of about 6.4kg, e.g. between 5.3 and 7.5 kg, or between 5.7 and 7.1 kg, or between6.0 and 6.8 kg, or even between 6.3 and 6.5 kg;

3) NUN 31208 WMW has an average mature fruit rind thickness at blossomend of about 5.9 mm, e.g. between 4.2 and 7.8 mm, or between 5.0 and 7.0mm or between about 5.5 and 6.5 mm, or even between about 5.8 and 6.0mm;

4) NUN 31208 WMW has an average mature fruit rind thickness at sides ofabout 9.6 mm, e.g. between 7.5 and 11.5 mm, or between 8 and 11 mm, orbetween 9.2 and 10.0 mm, or even between 9.5 and 9.7 mm;

5) NUN 31208 WMW has a maturity category 2—medium (e.g., 80-90 days);

6) NUN 31208 WMW has an average number of main stems at crown of about3.1, e.g. between 2.8 and 3.4, or between 2.9 and 3.3, or even between3.0 and 3.2;

7) NUN 31208 WMW has a mature fruit flesh color that is type 6—Dark Red(e.g., RHS code Red 39A); and,

8) NUN 31208 WMW has a mature fruit primary skin color that is type1—Yellow Green (Desert King) (e.g., RHS code Yellow Green 150D).

In still another aspect the invention provides a method of producing awatermelon plant, comprising crossing a plant of watermelon variety NUN31208 WMW with a second watermelon plant one or more times, andselecting progeny from said crossing.

In yet another aspect the invention provides a method of producing awatermelon plant, comprising selfing a plant of watermelon variety NUN31208 WMW one or more times, and selecting progeny from said selfing.

In other aspects, the invention provides for progeny of variety NUN31208 WMW such as progeny obtained by further breeding NUN 31208 WMW.Further breeding NUN 31208 WMW includes selfing NUN 31208 WMW one ormore times and/or cross-pollinating NUN 31208 WMW with anotherwatermelon plant or variety one or more times. In particular, theinvention provides for progeny that retain all the essentialmorphological and physiological characteristics of NUN 31208 WMW or thatretain one or more (e.g. 1) to 4) or 1) to 8) or all) of thedistinguishing characteristics of the watermelon type described furtherabove, or, in another embodiment, progeny that retain all morphologicaland physiological characteristics of NUN 31208 WMW as listed in Table 1;when grown under the same environmental conditions, when determined atthe 5% significance level. In another aspect, the invention provides forvegetative reproductions of the variety and plants having all but 1, 2,or 3 of the physiological and morphological characteristics of NUN 31208WMW (e.g. as listed in Table 1).

The morphological and/or physiological differences between plantsaccording to the invention, i.e. NUN 31208 WMW or progeny thereof, orplants having all but 1, 2, or 3 of the physiological and morphologicalcharacteristics of NUN 31208 WMW (as listed in Table 1); and other knownvarieties can easily be established by growing NUN 31208 WMW next to theother varieties (in the same field, under the same environmentalconditions), preferably in several locations which are suitable for saidwatermelon cultivation, and measuring morphological and/or physiologicalcharacteristics of a number of plants (e.g., to calculate an averagevalue and to determine the variation range/uniformity within thevariety). For example, trials can be carried out in Acampo Calif., USA(N 38 degrees 07′261″/W 121 degrees 18′ 807″, USA, whereby maturity,ploidy, plant sex form, leaf shape, leaf color, stem shape, surface andlength, flower size and color, fruit group, mature fruit color, fruitsize, fruit shape, rind texture and thickness, flesh texture and color,disease resistance, insect resistance, can be measured and directlycompared for species of Citrullus lanatus.

The morphological and physiological characteristics (and distinguishingcharacteristics) of NUN 31208 WMW, are provided in the Examples, inTable 1. Encompassed herein are also plants derivable from NUN 31208 WMW(e.g. by selfings and/or crossing and/or backcrossing with NUN 31208 WMWand/or progeny thereof) comprising all the physiological andmorphological characteristics of NUN 31208 WMW listed in Table 1 asdetermined at the 5% significance level when grown under the sameenvironmental conditions and/or comprising one or more (or all; or allexcept one, two or three) of the distinguishing characteristics asdetermined at the 5% significance level when grown under the sameenvironmental conditions.

Also at-harvest and/or post-harvest characteristics of fruits can becompared, such as cold storage holding quality, post-harvest rindfirmness and/or flesh firmness can be measured using known methods.

Flesh firmness can for example be measured using a penetrometer, e.g. byinserting a probe into the fruit flesh and determining the insertionforce, or by other methods.

The morphological and/or physiological characteristics may vary somewhatwith variation in the environment (such as temperature, light intensity,day length, humidity, soil, fertilizer use), which is why a comparisonunder the same environmental conditions is preferred. Colors can best bemeasured against The Munsell Book of Color (Munsell Color MacbethDivision of Kollmorgan Instruments Corporation) or using the RoyalHorticultural Society Chart (World wide web atrhs.org.uk/Plants/RHS-Publications/RHS-colour-charts).

In a preferred embodiment, the invention provides for watermelon fruitsof variety NUN 31208 WMW, or a part of the fruit. In another embodiment,the invention provides for a container comprising or consisting of aplurality of harvested watermelon fruits of NUN 31208 WMW, or progenythereof, or a derived variety.

In yet a further embodiment, the invention provides for a method ofproducing a new watermelon plant. The method comprises crossing a plantof the invention NUN 31208 WMW, or a plant comprising all but 1, 2, or 3of the morphological and physiological characteristics of NUN 31208 WMW(as listed in Table 1), or a progeny plant thereof, either as male or asfemale parent, with a second watermelon plant (or a wild relative ofwatermelon) one or more times, and/or selfing a watermelon plantaccording to the invention i.e. NUN 31208 WMW, or a progeny plantthereof, one or more times, and selecting progeny from said crossingand/or selfing. The second watermelon plant may for example be a line orvariety of the species Citrullus lanatus, or other Citrullus species oreven other Cucurbitacea species.

Progeny are a later generation (of seeds) produced from the first crossof the F1 hybrid with another plant (F2) or with itself (S2), or anyfurther generation produced by crossing and/or selfing (F3, F4, etc.)and/or backcrossing (BC2, BC3, etc.) one or more selected plants of theF2 and/or S2 and/or BC2 generation (or plants of any further generation,e.g. the F3) with another watermelon plant (and/or with a wild relativeof watermelon). Progeny may have all the physiological and morphologicalcharacteristics of watermelon variety NUN 31208 WMW when grown under thesame environmental conditions and/or progeny may have (be selected forhaving) one or more of the distinguishing characteristics of watermelonof the invention. Using common breeding methods such as backcrossing orrecurrent selection, one or more specific characteristics may beintroduced into NUN 31208 WMW, to provide or a plant comprising all but1, 2, or 3 or more of the morphological and physiologicalcharacteristics of NUN 31208 WMW (as listed in Table 1).

The invention provides for methods of producing plants which retain allthe morphological and physiological characteristics of NUN 31208 WMW.The invention provides also for methods of producing a plant comprisingall but 1, 2, or 3 or more of the morphological and physiologicalcharacteristics of NUN 31208 WMW (e.g. as listed in Table 1), but whichare still genetically closely related to NUN 31208 WMW. The relatednesscan, for example be determined by fingerprinting techniques (e.g.,making use of isozyme markers and/or molecular markers such as SNPmarkers, AFLP markers, microsatellites, minisatellites, RAPD markers,RFLP markers and others). A plant is “closely related” to NUN 31208 WMWif its DNA fingerprint is at least 80%, 90%, 95% or 98% identical to thefingerprint of NUN 31208 WMW. In a preferred embodiment AFLP markers areused for DNA fingerprinting (Vos et al. 1995, Nucleic Acid Research 23:4407-4414). A closely related plant may have a Jaccard's Similarityindex of at least about 0.8, preferably at least about 0.9, 0.95, 0.98or more (Gama et al., 2013. Horticultura Brasileira 31: 522-527). Theinvention also provides plants and varieties obtained by these methods.Plants may be produced by crossing and/or selfing, or alternatively, aplant may simply be identified and selected amongst NUN 31208 WMWplants, or progeny thereof, e.g. by identifying a variant within NUN31208 WMW or progeny thereof (e.g. produced by selfing) which variantdiffers from NUN 31208 WMW in one, two or three of the morphologicaland/or physiological characteristics (e.g. in one, two or threedistinguishing characteristics), e.g. those listed in Table 1 or others.In one embodiment the invention provides a watermelon plant having aJaccard's Similarity index with NUN 31208 WMW of at least 0.8, e.g. atleast 0.85, 0.9, 0.95, 0.98 or even at least 0.99.

By crossing and/or selfing also (one or more) single traits may beintroduced into the variety of the invention i.e. NUN 31208 WMW (e.g.,using backcrossing breeding schemes), while retaining the remainingmorphological and physiological characteristics of NUN 31208 WMW and/orwhile retaining one or more distinguishing characteristics. A singletrait converted plant may thereby be produced. For example, diseaseresistance genes may be introduced, genes responsible for one or morequality traits, yield, etc. Both single genes (dominant or recessive)and one or more QTLs (quantitative trait loci) may be transferred intoNUN 31208 WMW by breeding with NUN 31208 WMW.

Any pest or disease resistance genes may be introduced into a plantaccording to the invention, i.e. NUN 31208 WMW, progeny thereof or intoa plant comprising all but 1, 2, or 3 or more of the morphological andphysiological characteristics of NUN 31208 WMW (e.g. as listed in Table1). Resistance to one or more of the following diseases is preferablyintroduced into plants of the invention: Anthracnose, Downy Mildew,Fusarium Wilt, Gummy Stem Blight, Squash Mosaic, Watermelon Mosaic,Powdery Mildew, Cucumber Mosaic, Sunburn and Root Knot. Other resistancegenes, against pathogenic viruses, fungi, bacteria, nematodes, insectsor other pests may also be introduced.

Thus, invention also provides a method for developing a watermelon plantin a watermelon breeding program, using a watermelon plant of theinvention, or its parts as a source of plant breeding material. Suitableplant breeding techniques are recurrent selection, backcrossing,pedigree breeding, mass selection, mutation breeding and/or geneticmarker enhanced selection. For example, in one aspect, the methodcomprises crossing NUN 31208 WMW or progeny thereof, or a plantcomprising all but 1, 2, or 3 or more of the morphological andphysiological characteristics of NUN 31208 WMW (e.g. as listed in Table1), with a different watermelon plant, and wherein one or more offspringof the crossing are subject to one or more plant breeding techniquesselected from the group consisting of recurrent selection, backcrossing,pedigree breeding, mass selection, mutation breeding and genetic markerenhanced selection (see e.g. Zhang et al., HORTSCIENCE 31(1):123-126.1996). For breeding methods in general see Principles of Plant Geneticsand Breeding, 2007, George Acquaah, Blackwell Publishing, ISBN-13:978-1-4051-3646-4.

The invention thus also provides a method of introducing a single locusconversion, or single trait conversion or introducing a desired trait,into a watermelon plant according to the invention and/or into NUN 31208WMW comprising:

(a) crossing a watermelon plant of variety NUN 31208 WMW, arepresentative sample of seed of said variety having been depositedunder Accession Number NCIMB 42970, with a second watermelon plantcomprising a desired single locus to produce F1 progeny plants;(b) selecting F1 progeny plants that have the single locus;(c) crossing the selected progeny plants with a plant of NUN 31208 WMW,to produce backcross progeny plants;(d) selecting backcross progeny plants that have the single locus andone or more (or all) distinguishing characteristics of watermelonaccording to the invention and/or all the physiological andmorphological characteristics of NUN 31208 WMW to produce selectedbackcross progeny plants; and(e) optionally repeating steps (c) and (d) one or more times insuccession to produce selected second, third or fourth or higherbackcross progeny plants that comprise the single locus and otherwiseone or more (or all) the distinguishing characteristics of thewatermelons according to the invention and/or comprise all of thephysiological and morphological characteristics of NUN 31208 WMW, whengrown in the same environmental conditions. The invention furtherrelates to plants obtained by this method.

The above method is provided, wherein the single locus confers a trait,wherein the trait is pest resistance or disease resistance.

In one embodiment the trait is disease resistance and the resistance isconferred to Anthracnose, Downy Mildew, Fusarium Wilt, Gummy StemBlight, Squash Mosaic, Watermelon Mosaic, Powdery Mildew, CucumberMosaic, Sunburn and Root Knot.

The invention also provides a watermelon plant comprising at least afirst set of the chromosomes of watermelon variety NUN 31208 WMW, asample of seed of said variety having been deposited under AccessionNumber NCIMB 42970; optionally further comprising a single locusconversion, wherein said plant has essentially all of the morphologicaland physiological characteristics of the plant comprising at least afirst set of the chromosomes of watermelon NUN 31208 WMW. In anotherembodiment, this single locus conversion confers a trait selected fromthe group consisting of male sterility, herbicide tolerance, insectresistance, pest resistance, disease resistance, environmental stresstolerance, modified carbohydrate metabolism and modified proteinmetabolism.

In one embodiment, NUN 31208 WMW may also be mutated (by e.g.irradiation, chemical mutagenesis, heat treatment, etc.) and mutatedseeds or plants may be selected in order to change one or morecharacteristics of NUN 31208 WMW. Methods such as TILLING may be appliedto watermelon populations in order to identify mutants. Similarly, NUN31208 WMW may be transformed and regenerated, whereby one or morechimeric genes are introduced into the variety or into a plantcomprising all but 1, 2, 3, or more of the morphological andphysiological characteristics (e.g. as listed in Table 1).Transformation can be carried out using standard methods, such asAgrobacterium tumefaciens mediated transformation or biolistics,followed by selection of the transformed cells and regeneration intoplants. A desired trait (e.g. genes conferring pest or diseaseresistance, herbicide, fungicide or insecticide tolerance, etc.) can beintroduced into NUN 31208 WMW, or progeny thereof, by transforming NUN31208 WMW or progeny thereof with a transgene that confers the desiredtrait, wherein the transformed plant retains all the phenotypic and/ormorphological and/or physiological characteristics of NUN 31208 WMW orthe progeny thereof and contains the desired trait.

The invention also provides for progeny of watermelon hybrid (F1)variety NUN 31208 WMW obtained by further breeding with NUN 31208 WMW.In one aspect progeny are F2 progeny obtained by crossing NUN 31208 WMWwith another plant or S2 progeny obtained by selfing NUN 31208 WMW. Alsoencompassed are F3 progeny obtained by selfing the F2 plants. “Furtherbreeding” encompasses traditional breeding (e.g., selfing, crossing,backcrossing), marker assisted breeding, and/or mutation breeding. Inone embodiment, the progeny have one or more (or all) of thedistinguishing characteristics mentioned further above when grown underthe same environmental conditions. In a further embodiment the progenyhave all the physiological and morphological characteristics of varietyNUN 31208 WMW when grown under the same environmental conditions. Inanother embodiment the progeny have one, two, or three distinct traits(qualitative or quantitative) introduced into NUN 31208 WMW, whileretaining all the other physiological and morphological characteristicsof variety NUN 31208 WMW when grown under the same environmentalconditions.

The invention also provides a plant having one, two or threephysiological and/or morphological characteristics which are differentfrom those of NUN 31208 WMW and which otherwise has all thephysiological and morphological characteristics of NUN 31208 WMW,wherein a representative sample of seed of variety NUN 31208 WMW hasbeen deposited under Accession Number NCIMB 42970. In particular plantswhich differ from NUN 31208 WMW in none, one, two or three of thecharacteristics mentioned in Table 1 are encompassed.

In one aspect, the plant having one, two or three physiological and/ormorphological characteristics which are different from those of NUN31208 WMW and which otherwise has all the physiological andmorphological characteristics of NUN 31208 WMW differs from NUN 31208WMW in one, two or three of the distinguishing morphological and/orphysiological characteristics selected from 1) average mature fruitlength; 2) average mature fruit average weight; 3) average mature fruitrind thickness at blossom end; 4) average mature fruit rind thickness atsides; 5) maturity category; 6) average number of main stems at crown;7) mature fruit flesh color; and, 8) mature fruit primary skin color.

In another embodiment the plant having one, two or three physiologicaland/or morphological characteristics which are different from those ofNUN 31208 WMW and which otherwise has all the physiological andmorphological characteristics of NUN 31208 WMW differs from NUN 31208WMW in one, two or three morphological or physiological characteristicother than the “distinguishing morphological and/or physiologicalcharacteristics” (or essential physiological and/or morphologicalcharacteristics) of NUN 31208 WMW selected from: 1) average mature fruitlength; 2) average mature fruit average weight; 3) average mature fruitrind thickness at blossom end; 4) average mature fruit rind thickness atsides; 5) maturity category; 6) average number of main stems at crown;7) mature fruit flesh color; and, 8) mature fruit primary skin color.

Watermelons according to the invention, such as the variety NUN 31208WMW, or its progeny, or a plant having all physiological and/ormorphological characteristics but one, two or three which are differentfrom those of NUN 31208 WMW, can also be reproduced using vegetativereproduction methods. Therefore, the invention provides for a method ofproducing plants, or a part thereof, of variety NUN 31208 WMW,comprising vegetative propagation of variety NUN 31208 WMW. Vegetativepropagation comprises regenerating a whole plant from a plant part ofvariety NUN 31208 WMW (or from its progeny or from or a plant having allphysiological and/or morphological characteristics but one, two orthree, which are different from those of NUN 31208 WMW), such as acutting, a cell culture or a tissue culture.

The invention also concerns methods of vegetatively propagating a plantof the invention. In certain embodiments, the method comprises the stepsof: (a) collecting tissue or cells capable of being propagated from aplant of the invention; (b) cultivating said tissue or cells to obtainproliferated shoots; and (c) rooting said proliferated shoots, to obtainrooted plantlets. Steps (b) and (c) may also be reversed, i.e. firstcultivating said tissue to obtain roots and then cultivating the tissueto obtain shoots, thereby obtaining rooted plantlets. The rootedplantlets may then be further grown, to obtain plants. In oneembodiment, the method further comprises step (d) growing plants fromsaid rooted plantlets

The invention also provides for a vegetatively propagated plant ofvariety NUN 31208 WMW (or from its progeny or from or a plant having allbut one, two or three physiological and/or morphological characteristicswhich are different from those of NUN 31208 WMW, or a part thereof,having one or more distinguishing characteristics and/or all themorphological and physiological characteristics of NUN 31208 WMW (exceptfor the characteristics differing), when grown under the sameenvironmental conditions.

Parts of NUN 31208 WMW (or of its progeny or of a plant having allphysiological and/or morphological characteristics but one, two or threewhich are different from those of NUN 31208 WMW) encompass any cells,tissues, organs obtainable from the seedlings or plants, such as but notlimited to: watermelon fruits or parts thereof, cuttings, hypocotyl,cotyledon, pollen, scion and the like. Such parts can be stored and/orprocessed further. Encompassed are therefore also food or feed productscomprising one or more of such parts, such as canned, chopped, cooked,roasted, preserved, frozen, dried, pickled, or juiced watermelon fruitfrom NUN 31208 WMW or from progeny thereof, or from a derived variety,such as a plant having all but one, two or three physiological and/ormorphological characteristics which are different from those of NUN31208 WMW.

In one aspect haploid plants and/or double haploid plants of NUN 31208WMW, or a plant having all but one, two or three physiological and/ormorphological characteristics which are different from those of NUN31208 WMW, or progeny of any of these, are encompassed herein. Haploidand double haploid (DH) plants can, for example, be produced by cell ortissue culture and chromosome doubling agents and regeneration into awhole plant. For DH production chromosome doubling may be induced usingknown methods, such as colchicine treatment or the like.

Also provided are plant parts derived from variety NUN 31208 WMW (orfrom its progeny or from a plant having all but one, two or threephysiological and/or morphological characteristics which are differentfrom those of NUN 31208 WMW D), or from a vegetatively propagated plantof NUN 31208 WMW (or from its progeny or from a plant having all butone, two or three physiological and/or morphological characteristicswhich are different from those of NUN 31208 WMW), being selected fromthe group consisting of: harvested fruits or parts thereof, pollen,cells, leaves or parts thereof, petioles, cotyledons, hypocotyls, shootsor parts thereof, stems or parts thereof, or vines or parts thereof,roots or parts thereof, cuttings, or flowers.

In one embodiment, the invention provides for extracts of a plantdescribed herein and compositions comprising or consisting of suchextracts. In a preferred embodiment, the extract consists of orcomprises tissue of a plant described herein or is obtained from suchtissue.

In still yet another aspect, the invention provides a method ofdetermining the genotype of a plant of the invention comprisingdetecting in the genome (e.g., a sample of nucleic acids) of the plantat least a first polymorphism. The method may, in certain embodiments,comprise detecting a plurality of polymorphisms in the genome of theplant, for example by obtaining a sample of nucleic acid from a plantand detecting in said nucleic acids a plurality of polymorphisms. Themethod may further comprise storing the results of the step of detectingthe plurality of polymorphisms on a computer readable medium

The invention also provides for a food or feed product comprising orconsisting of a plant part described herein wherein the plant part canbe identified as a part of the plant of the invention. Preferably, theplant part is a watermelon fruit or part thereof and/or an extract froma fruit or another plant part described herein. The food or feed productmay be fresh or processed, e.g., dried, grinded, powdered, pickled,chopped, cooked, juiced, preserved, pickled, or powdered canned,steamed, boiled, blanched and/or frozen, etc.

For example, containers such as cans, boxes, crates, bags, cartons,Modified Atmosphere Packagings, films (e.g. biodegradable films), etc.comprising plant parts of plants (fresh and/or processed) describedherein are also provided herein.

Marketable watermelon fruits are generally sorted by size and qualityafter harvest. Alternatively the watermelon fruits can be sorted by Brixor sugar content.

Watermelons may also be grown for use in grafting or inosculation asrootstocks (stocks) or scions (scions). Typically, different types ofwatermelons are grafted to enhance disease resistance, which is usuallyconferred by the rootstock, while retaining the horticultural qualitiesusually conferred by the scion. It is not uncommon for grafting to occurbetween cultivated watermelon varieties and related Citrullus species.Methods of grafting and vegetative propagation are well-known in theart.

So in one aspect the invention relates to a plant comprising a rootstockor scion of NUN 31208 WMW.

Using methods known in the art like “reverse breeding”, it is possibleto produce parental lines for a hybrid plant such as NUN 31208 WMW;where normally the hybrid is produced from the parental lines. Suchmethods are based on the segregation of individual alleles in the sporesproduced by a desired plant and/or in the progeny derived from theself-pollination of that desired plant, and on the subsequentidentification of suitable progeny plants in one generation, or in alimited number of inbred cycles. Such a method is known fromWO2014076249 or from Nature Protocols Volume: 9, Pages: 761-772 (2014)DOI: doi:10.1038/nprot.2014.049, which are enclosed by reference. Suchmethod for producing parental lines for a hybrid organism, comprises thesteps of: a) defining a set of genetic markers that are present in aheterozygous form (H) in a partially heterozygous starting organism; b)producing doubled haploid lines from spores of the starting organism: c)genetically characterizing the doubled haploid lines thus obtained forthe said set of genetic markers to determine whether they are present ina first homozygous form (A) or in a second homozygous form (B); d)selecting at least one pair of doubled haploid lines that havecomplementary alleles for at least a subset of the genetic markers,wherein each member of the pair is suitable as a parental line for ahybrid organism.

Thus in one aspect, the invention relates to a method of producing acombination of parental lines of a plant of the invention (NUN 31208WMW) comprising the step of making double haploid cells from haploidcells from the plant of the invention (NUN 31208 WMW) or a seed of thatplant; and optionally crossing these parental lines to produce andcollect seeds. In another aspect, the invention relates to a combinationof parental lines produced by this method. In still another aspect saidcombination of parental lines can be used to produce a seed or plant ofNUN 31208 WMW when these parental lines are crossed. In still anotheraspect, the invention relates to a combination of parental lines fromwhich a seed or plant having all but one, two or three physiologicaland/or morphological characteristics of NUN 31208 WMW can be produced;or in another aspect, wherein a seed or plant having the distinguishingcharacteristics 1)-4) or 1)-8) of NUN 31208 WMW, as herein defined, canbe produced when grown under the same environmental conditions. In stillanother aspect, the invention relates to a combination of parental linesfrom which a seed or plant having all the characteristics of NUN 31208WMW as defined in Table 1 can be produced when grown under the sameconditions.

All documents (e.g., patent publications) are herein incorporated byreference in their entirety. Cited references:

-   Acquaah, Principles of Plant Genetics and Breeding, 2007, Blackwell    Publishing, ISBN-13: 978-1-4051-3646-4-   Kihara, 1951, Proceedings of American Society for Horticultural    Science 58: 217-230;-   ams.usda.gov/AMSv1.0/getfile?dDocName=STELDEV3003768    on the world wide web at    rhs.org.uk/Plants/RHS-Publications/RHS-colour-charts    on the world wide web upov.int/edocs/tgdocs/en/tg076.pdf    Eigsti 1971, Hort Science 6: 1-2-   GAMA RNCS; SANTOS CAF; DIAS RCS; SOUZA FF. 2013. Molecular    characterization of watermelon cultivars using microsatellite    markers. Horticultura Brasileira 31: 522-527.-   Zhang et al., HORTSCIENCE 31(1):123-126. 1996-   Compton et al., Plant Cell, Tissue and Organ Culture 77: 231-243,    2004    US 2006/0168701-   Principles of Plant Genetics and Breeding, 2007, George Acquaah,    Blackwell Publishing, ISBN-13: 978-1-4051-3646-4-   WO2014076249-   Vos et al. 1995, Nucleic Acid Research 23: 4407-4414-   Nature Protocols Volume: 9, Pages: 761-772 (2014) DOI:    doi:10.1038/nprot.2014.049

EXAMPLES Development of NUN 31208 WMW

The hybrid NUN 31208 WMW was developed from a male and femaleproprietary inbred line of Nunhems. The female and male parents werecrossed to produce hybrid (F1) seeds of NUN 31208 WMW. The seeds of NUN31208 WMW can be grown to produce hybrid plants and parts thereof (e.g.watermelon fruit). The hybrid NUN 31208 WMW can be propagated by seedsor vegetative.

The hybrid variety is uniform and genetically stable. This has beenestablished through evaluation of horticultural characteristics. Severalhybrid seed production events resulted in no observable deviation ingenetic stability. Coupled with the confirmation of genetic stability ofthe female and male parents the Applicant concluded that NUN 31208 WMWis uniform and stable.

DEPOSIT INFORMATION

A total of 2500 seeds of the hybrid variety NUN 31208 WMW were depositedaccording to the Budapest Treaty by Nunhems B.V. on Feb. 13, 2018, atthe NCIMB Ltd., Ferguson Building, Craibstone Estate, Bucksburn,Aberdeen AB21 9YA, United Kingdom (NCIMB). The deposit has been assignedNCIMB 42970. A deposit of NUN 31208 WMW and of the male and femaleparent line is also maintained at Nunhems B.V. Access to the depositwill be available during the pendency of this application to personsdetermined by the Director of the U.S. Patent Office to be entitledthereto upon request. Subject to 37 C.F.R. § 1.808(b), all restrictionsimposed by the depositor on the availability to the public of thedeposited material will be irrevocably removed upon the granting of thepatent. The deposit will be maintained for a period of 30 years, or 5years after the most recent request, or for the enforceable life of thepatent whichever is longer, and will be replaced if it ever becomesnonviable during that period. Applicant does not waive any rightsgranted under this patent on this application or under the Plant VarietyProtection Act (7 USC 2321 et seq.).

The most similar variety to NUN 31208 WMW is Liberty, a commercialvariety from US Agriseeds. In Table 1 a comparison between NUN 31208 WMWand Liberty is shown based on a trial in the USA. Trial location: AcampoCalif. USA, (coordinates: 38.192873° N,−121.232637° W). Seeding date:Jul. 2, 2015, transplanting date: Aug. 4, 2014, harvesting date Oct. 23,2014.

Two replications of 50 plants each, from which 15 plants or plant partswere randomly selected to measure characteristics. In Table 1 the USDAdescriptors of NUN 31208 WMW (this application) and reference Liberty(commercial variety) are summarized.

TABLE 1 USDA descriptor NUN 31208 WMW Liberty 1. General Fruit TypeFruit type: 1 = Oblong, 2 = Round Large, 3 = Round 4 4 small (icebox), 4= Other 2. Area of best adaptation Region: 1 = Southern U.S., 2 =Northeast/Central U.S., 4 4 3 = Southwest U.S., 4 = Most U.S. Areas, 5 =other 3. Maturity No. of days from emergence to anthesis NA NA No. ofdays from pollination to maturity NA NA Days Relative Maturity (asreported in seed catalogs) 80-90 78-80 Maturity category: 1 = early, 2 =medium, 3 = late 2 1 4. Ploidy 1 = diploid, 2 = tetraploid, 3 = triploid3 3 5. Plant Cotyledon shape: 1 = flat, 2 = folded NA NA Plant sex form:1 = monoecious, 2 = andromonoecious 1 1 No. of main stems at crown 3.13.5 6. STEM Stem shape (cross section:) 1 = round, 2 = angular 2 2Diameter (mm) at second node NA NA Stem surface: 1 = glabrous, 2 =scabrous, 3 = pubescent, 3 3 4 = bristled Vine length (cm) (at lastharvest) NA NA No. of Internodes (at last harvest) NA NA Ratio Vinelength (cm): No of internodes (at last harvest) NA NA 7. LEAF Leafshape: 1 = ovate, 2 = obovate, 3 = round 1 1 Leaf lobes: 1 = none, 2 =lobed 2 2 Leaf length (cm) 15.9 16.3 Leaf width (cm) 15.2 14.8 Leafsize: 1 = longer than wide, 2 = length-width equal, 1 1 3 = wider thanlong Dorsal surface pubescence: 1 = smooth, 2 = pubescent 2 2 Ventralsurface pubescence: 1 = smooth, 2 = pubescent 2 2 Leaf color: 1 = lightgreen, 2 = gray green, 3 = medium 3 3 green, 4 = dark green Color chartvalue (RHS): Green 137A Green 137A 8. FLOWER Diameter across Staminate(cm) 3.6 3.7 Diameter across Pistillate (cm) 3.4 3.8 Flower color: 1 =lemon, 2 = yellow, 3 = orange 2 2 Color chart value (RHS) Yellow 8BYellow 8B 9. MATURE FRUIT Fruit shape: 1 = round, 2 = oval, 3 =cylindrical 2 2 Long (cm) 24.3 26.1 Diameter at midsection (cm) 20.621.4 Average weight (kg) 6.4 7.7 Maximum fruit weight (kg) 8.2 9.4 Index= length ÷ diameter × 10 11.8 12.2 Fruit surface: 1 = smooth, 2 =slightly grooved, 3 = deeply 1 1 grooved Skin color pattern: 1 = solid(one color), 2 = stripe, 2 2 3 = mottle/net Primary color: 1 = YellowGreen (Desert King), 2 = Light 1 2 Green (Charleston Gray), 3 = MediumGreen (Sugar baby), 4 = dark green (Florida Giant) Color chart value(RHS chart) Yellow Green 150D Yellow Green N144D Secondary color 3 3 1 =Yellow Green, 2 = Light Green, 3 = Medium green, 4 = dark green Colorchart value (RHS chart) Green 137A Green 137B 10. RIND Rind texture: 1 =tender, 2 = brittle, 3 = tough 3 3 Thickness blossom end (mm) 5.9 7.9Thickness sides (mm) 9.6 12.0 11. FLESH Flesh texture: 1 = crisp, 2 =soft 1 1 Flesh coarseness: 1 = course fibrous, 2 = fine—little fiber 2 2Flesh color: 1 = white, 2 = yellow, 3 = orange, 4 = pink, 6 4 5 = red, 6= dark red Color chart value (RHS chart) Red 39A Red 37A Refractometer:% Soluble solids of juice (Center of fruit) 9.8 9.6 % Hollow heart 0 6.6% Placental separation 6.6 20 % Transverse crack 0 0These are typical values. Values may vary due to environment. Othervalues that are substantially equivalent are also within the scope ofthe invention. N.A.=not applicable; n.r.=not recorded.The leaf petiole diameter was also determined in NUN 31208 WMW andreference Liberty (commercial variety) (Table 2).

TABLE 2 NUN 31208 WMW Liberty Petiole diameter (leaf) in cm 9.9 10.5These are typical values. Values may vary due to environment. Othervalues that are substantially equivalent are also within the scope ofthe invention.

The invention claimed is:
 1. A plant, plant part or seed of watermelonvariety NUN 31208 WMW, wherein representative seed of said variety hasbeen deposited under Accession Number NCIMB
 42970. 2. A plant or partthereof grown from the seed of claim
 1. 3. The plant part of claim 2,further defined as a leaf, pollen, an ovule, a fruit, a scion, arootstock, cutting, flower or a part of any of these or a cell.
 4. Atissue or cell culture of regenerable cells of the plant of claim
 2. 5.The tissue or cell culture according to claim 4, comprising cells orprotoplasts from a plant part selected from the group consisting ofembryos, meristems, cotyledons, hypocotyl, pollen, leaves, anthers,roots, root tips, pistil, petiole, flower, fruit, seed, stem and stalks.6. A watermelon plant regenerated from the tissue or cell culture ofclaim 4, wherein the plant has all of the physiological andmorphological characteristics of the plant of claim 2 when determined atthe 5% significance level for plants grown under the same environmentalconditions.
 7. A method of producing of the plant of claim 2, or a partthereof, comprising vegetative propagation of the plant of claim
 2. 8.The method of claim 7, wherein said vegetative propagation comprisesregenerating a whole plant from a plant part of watermelon variety NUN31208 WMW, wherein representative seed of said variety has beendeposited under Accession Number NCIMB
 42970. 9. The method of claim 7,wherein said part is a cutting, a cell culture or a tissue culture. 10.A vegetative propagated plant, propagated from the plant part of claim2, or a part said propagated plant, wherein the plant has all of thephysiological and morphological characteristics of the plant of claim 2when determined at the 5% significance level for plants grown under thesame environmental conditions.
 11. A food or feed product comprising theplant part of claim
 3. 12. A plant, plant part or seed of watermelonvariety NUN 31208 WMW, wherein a representative sample of seed of saidvariety has been deposited under Accession Number NCIMB 42970, andwherein said plant, plant part or seed comprises a single locusconversion, but otherwise has all of the morphological and physiologicalcharacteristics of NUN 31208 WMW when grown under the same environmentalconditions, optionally wherein the single locus conversion confers atrait selected from the group consisting of male sterility, herbicidetolerance, insect resistance, pest resistance, disease resistance,environmental stress tolerance, modified carbohydrate metabolism andmodified protein metabolism.
 13. A plant comprising the scion orrootstock of claim
 3. 14. A method of making doubled haploids of theplant of watermelon variety NUN 31208 WMW, wherein a representativesample of seed of said variety has been deposited under Accession NumberNCIMB 42970 comprising the step of making double haploid cells fromhaploid cells from the plant of claim 10 or a seed of claim 1.